Incineration



Nov. 29, 1938.

w. RAISCH 2,138,120

I INCINERATION Filed Oct. 50, 1956 2 Sheets-Sheet 1 INVENTOR V M [[am Raise/2 h ATTORNEY Nov. 29, 1938.,

w. RAISCH 2,138,120 INCINERATION Filed Oct. 30, 1936 2 Sheets-Sheet 2 IINVENTOR [/zam Acusch A; ATTORNEY Patented Nov. 29, 1938 V UNITED snares rater OFFICE INCINERATIION William Raiseh, New York, N. Y., assignor to Underpinning & Foundation 00., Inc., New York, N. Y., a corporation of New York Application October 30, 1936, Serial No. 108,428

1 Claim. (01. 110-13) The present invention relates to incineration Fig. 2 is a section taken on the line 22 of and more particularly to apparatus of the multi- Fig. 1;

ple-hearth type and to a'process involving a pre- Fig. 3 is a section taken on the line 3-3 of liminary or drying stage in which moisture and Fig. 1; and g 5 volatile constituents are driven off from the ma- Fig. 4 is a section taken on the line 4-4 of 5 terial to be treated, as by subjecting the material Fig. l. r

to heating and contact with a stream of air, pref- Referring to the drawings, the invention may ably preheated and a final stage in which the be embodied in a furnace having a multiple dried material is completely burned. hearth drying section provided with a top II,

10 The principal objects are to provide novel, adhearths I2, I3, I4, I and I6 carried by periph- 10 vantageous, and efficient forms of apparatus and eral Wall H of the furnace. The furnace also processes for effecting treatment of the general includes a burning section provided With a grate character specified. I6 having a raised center and a sloping grate While applicable to the treatment of various surface down which the ashes will Work to a i5 materials, the present invention is particularly peripheral channel I9 provided with discharge adapted for the disposal and destruction of waste chutes 2|] normally closed by gates or slides 2 I.

materials such as garbage and sewage solids in The material to be treated may be introduced the form of sludge or in the form of screenings into the furnace and deposited upon the upperhaving high moisture content. most hearth I2 through a hopper 22' and chute In carrying out the invention, use may be made 23 extending through the top II of the furnace 20 of a vertical furnace having an upper drying secand provided with a pivoted door or gate 24 nortion of the tiered multiple-hearth type comprising mally held in closed position by suitable .means vertically spaced hearths with outlets at the censuch as a Weighted. arm 25. As soon as a sufter of one and at the periphery of the next adficient amount of material to overcome the ac- 25 joining hearth either above or below, the lowertion of the weighted arm 25 collects on the door 25 most hearth having a central opening, and a or gate 24, the door swings downwardly about burning section having a grate with a raised oenitts pivotal sgippolrt gn'dhperfi ilitgsz thZ mlziteiialt 051 tral portion and a grate surface inclined downhe door to all 0 t e ear s i us ra e wardly from the raised central portion toward this material falls on the hearth 82 near its pethe sides of the furnace. t rirphery and is wggkeg. irrrwatrldlyttlf {az cgntraltdk'rsl- 30 Also air, preferably preheated, is introduced a c arge opening 0 e ear y sui a e the top of the drying section and withdrawn from rabbling means including one or more radial the lower part thereof, and air, preferably prearms 2? and inclined blades 28. heated, is introduced beneath the burning or fire Below the hearth I2 the hearths I3 and I5 are grate and passed upwardly therethrough, the provided with peripheral outlets 29 and the 35 gases of combustion being withdrawn from the hearths It and I6 are provided with central outupper part of the burning section. Burners may lets 2%, corresponding to that of the hearth I2. be used wherever needed to heat the various com- The material 011 the hearths l5 d 6 partrnents of the drying section or the main comis moved towards the corresponding t ets by 40 partment of the burning section If desired the suitable rabbhng means similar to that above'gg air and vapors passing from the drying section the heargh the blades pv i hearths may be introduced beneath the grate of the burnm and having the same mclmetlon as those a above the hearth l2, and the blades 28above the mg section to aid combustion and insure the ellmf noxious odors when the canditions hearths i3 and Io being so inclined as to carry matlon o the material outwardly on the corresponding 4.5

are such that Obnoxlous Odors Produced hearths to the peripheral outlets 29. The rabby treatment m the r an Wlthdrawn bling arms 21 are supported and operated by flfom the dryer may be discharged to the Open means of a hollow vertical shaft 30 passing an. through the central parts of the central outlets other obiecis, {features and advantages W111 28 of the hearths I2, 14 and i6 and through 50 appear upon cons1deration of the following desmaller openings in the top H and the hearths Scription and 0f the drawings in Which: I3 and I5, suitable gas seals being provided where Fi 1 is a v r l section f a furnace mthe shaft 30 passes through the top H and the bodying the present invention in a preferred hearths I3 and I5.

form; Air may be supplied to the interior of the shaft 55 through a duct 3| and the shaft may be rotated by means including a bevel gear 32 thereon, a bevel gear 33 meshing with the bevel gear 32, a motor 34 and a speed changer 35 interposed in the driving connection between the motor 34 and the bevel gear 33. In the drying section there may be provided a duct 36 communicating with the uppermost compartment of the drying section and a duct 31 communicating with the lowermost compartment of the drying section. Air prefererably preheated may also be supplied beneath the grate l8 by means including a manifold or distributing ring 38 and branch ducts 39 passing through a floor 40.

The floor 40 is attached to an annular channel member 4| which serves as part of a support for grate members 42 having inclined radial members 43 extending from the annular member ll upwardly to an annular member or ring 44 surrounding the reduced lower end 45 of the shaft 30. The supporting structure for the grate members 42 also includes a ring 46 connecting the radially extending members 43 and supporting the inner ends of inclined radial members 4'! attached at their other ends to the annular member 4i. At its upper edge the annular member 4! is attached toa flat annular member 48 which in turn is supported by an annular member 49 resting on the inner edge of a flat annular member 50 supoprted in the wall ll of the furnace ID.

The members 42 are preferably in the form of flat blocks with channels in their lower sides and may be of any suitable material such as cast iron. In assembling the grate a row of the blocks or grate members 42 which are suitably curved, is

placed on a fiat annular member 48 in the form of a circle and this circular arrangement of blocks serves to support a corresponding circle of blocks of slightly less diameter, the blocks being arranged to rest at their inner edges on the inclined radial members 43 and 41. This building up is continued until the stepped grate is completed. Over the uppermost circle of blocks 42 is an annular member 5| which serves as part of a gas seal 52.

The air entering through the duct 36 may be preheated and as it enters the drying section may be brought to any suitable temperature is any suitable manner as by the addition of cooled air.

By keeping the temperature in the drying section from exceeding a certain upper limit, the production of gases with noxious odors may in many cases be avoided. In the event, however, that noxious odors are produced by the drying of the material in the drying zone, the air laden with such gases and odors may be drawn out through the duct 3? and introduced into the manifold 38 from which it will pass into the space beneath the hearth members 42.

It should be noted that due to the maintenance of communication between the dryer and the burning furnace through the outlet 26 in the lowermost hearth l6, there may be an interchange of air and gases through the hearth I6.

Doors 53 may be provided for -any of the compartments and also burners 54 may be provided for any or all of the hearths in the drying and burning sections.

In general, the operation is substantially as follows: Material thrown into the hopper 22 falls on the pivoted gate 24 and when its weight becomes great enough to overcome the resistance by weighted arm 25, the door 24 will open and the material will fall to the hearth l2 and will be gradually rabbled or worked inwardly to the central outlet 26 where it will pass downwardly into the next lower compartment. The material will then be worked outwardly along the hearth I3 to the outlet or outlets 29, inwardly on the surface of the hearth I4, outwardly on the hearth l5, and inwardly on the hearth l6.

At starting or any other time, the temperature may be raised by use of suitable means such asburners 54 provided at some or all of the compartments in the drying and burning sections of the furnace. Preheated air may be passed at any suitable temperature into the uppermost zone of the furnace, passed downwardly through the furnace and then withdrawn from the furnace through the pipe 27. The material in the drying section gradually works down to the hearth l6 and will then be rabbled through the opening 25 to the fire grate I 8 which is arranged so as to facilitate heating and burning of the material and the gradual working down of the material to the side wall of the furnace. During the burning of material in the furnace I8 the air either preheated or otherwise may be passed upwardly into the space beneath the hollow hearth grate structure and after passing through the openings in the grate members 42 and through the bed of burning material thereon, will pass outwardly through the duct 55. As the combustible material burns, at its upper surface it will gradually work down along the sloped incline into the channel I9 and will then be discharged from the apparatus.

It should be understood that various changes may be made in the construction and arrangement and that certain parts may be used without others without departing from the true scope and spirit of the invention.

Having thus described my invention, I claim:

In a furnace of the class described, a drying section separated into compartments by a plurality of vertically spaced hearths of which alternate hearths have central outlets and peripheral outlets respectively and the lowermost hearth is one with a permanently open central outlet, a burning section having a conical grate receiving dried material directly through said permanently open central outlet, an air inlet at the upper part of said drying section, an air outlet for discharging from the interior of the furnace air and vapor from the lower part of the drying section, a combustion gas outlet at the upper part of said burning section, and air-supply means below said grate.

WILLIAM RAISCH. 

